Pulverizer



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- PULVERIZER Filed July .19, 1929,

Inventdr T ViVl/TPez/fi/ibane By g2; z: v i 'Ailomcys Patented Oct. 14, 1930 WALTER'W. PETTIBONE, or BIRMINGHAM, ALABAMA PULVERIZER Application filed July 19, 1929. Serial No. 379,462.

My invention relates to pulve-rizers and like means for reducing coal, minerals and other materials, and its object is to provide bafile means to prevent centrifugal ejection of material through the supplemental air inlets provided adjacent to the fan chamber from which the finished material is blown to discharge it from the pulverizer.

In pulverizers, the material under treatment after passing through the required number of reduction stages is delivered to a discharge chamber from which it is blown by a fan to the point of use and it has been found necessary to interpose a supplemental air inlet chamber adjacent to the fan chamber to permit of the functioning properly in the discharge of the pulverized material.

In practice it has been found that there is a tendency of the whirling mass of material responsive to centrifugal force, to separate more or less of the larger particles from the reduced mass flowing to the fan chamber and to eject such particles through the supplemental air inlet ports, and the particular obj ect of this invention is to prevent this and to return such separated particles to the machine for further reduction.

My invention contemplates the provision, in a peripheral wall of the supplemental air inlet chamber, of air inlet openings which are guarded by inwardly inclined deflector lips or flanges adapted to deflect whirling particles of material so that they will jump ir inlet openings and thus I avoid the wasting of material through the air openings without interfering with the free inflow of air.

A further object is to take advantage of the fact that the coarser unreduced particles of material alone will reach the outer peripheral wall of the supplemental air inlet chamber, and by adapting the baffles to deflect these larger whirling particles inwardly they will tend to become separated from the finer material passing to the fan chamber and because of the proper relation of the inlet and outlet openings for said supplemental air chamber, these coarser particles will be returned to the last treatment chamber and there acted upon to complete their reduction.

My invention further comprises the novel details ot construction and arrangements of parts which are hereinafter more particularly described and claimed and which, in their preferred embodiment only, are illustrated v plemental air inlet chamber 8 which in turn is subdivided by an annular partition 9 from the chamber 10in which the fan llis mounted. This fan, driven by shaft 12, acts in a manner, well understood in this art, to draw in the reduced material along with the supplemental supply of air entering the air inlet chamber and deliver said material through a suitable discharge 13 to the point of use. All the parts thus far described are of standard construction and may be widely varied '3 according to conditions of use.

I show the supplemental air inlet chamber 8 formed with an outer peripheral wall lei which separates said chamber from an annular air supply chamber 15 having openii 16, preferably in its outer side wall at diametrically opposite points, to admit thereto the supplemental supply of air. The wall 14 of the air chamber has any desired number of air inlet ports 17 and each port on i the side of the approach of the whirling ma terial, has an inwardly inclined deflector lip or bailie 18, which extends a sufficient dis tance inwardly from the outer wall to cause any particles of the pulverized material, that gain access to the air chamber and are caused to whirl therein, to be sufficiently deflected inwardly to jump the air ports and he retained within the machine. 'These deflectors are preferably coextensive in width with the lUU air chamber 8 and in the construction shown are formed by inclining the outer marginal wall 14: inwardly on the approach side of each air inlet port to a point close to the inner edge 01": the annular partition 7.

It will be'noted that the opening in the annular partition 7, through which material enters the supplemental air inlet chamber, is materially greater in diameter than the opening in partition 9 giving into the fan chamber. Preferably the batlles 18 extend close to the opening in partition 7 and as a result of this arrangement it will be seen that any particles arrested by the battles will tend to pass back into the last treatment chamber and not to pass into the tan chamber with the reduced material. By taking advantage of this construction the deflectors will cause such larger unreduced particles as may escape from the flow of material to the tan chamber to be returned and where necessary be further reduced, thus preventing their accumulation within the machine or their escapes therefrom through the air inlet opening.

In ope ation, the great mass of reduced material passes directly across the supplemental air inlet hamber into the fan chamber and is discharged, but all of the material is traveling in a whirl about the axis of the pulverizcr and this whirl causes the arger, heavier particles to collect about the periphery of the mass under treatment and thus they become separated from the reduced material an d gain access to the outer periphery of the supplemental air inlet chamber. As they whirl in this chamber they engage the deflectors and are thrown back toward the center of the machine where, it fine enough, they will pass out to the tan chamber or it coarse they will pass back into the last treatment ch amber and become subject to further reduction.

lVhile l have shown the outer wall and deflectors of the air treatment chamber formed by a casting integral with the it housing, it is to be understood that the equi alcnt of this wall can be applied to an existing pulverizer in any suitable and economical way adapted to effect the deflection of the whirling material sufficiently to jump the supplemental air inlet ports.

While l have shown my invention in but one term it will-be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit thereof and I desire tl eretore that only such limitations shall be placed thereupon as are imposed by the prior art, or as are specifically set forth in the appended claims.

lVhat I claim is:

1. In a pulverizer, a casing divided by transverse annular partitions into chambers successively adapted for the reduction of material, the inlet of supplemental air, and the discharge by a fan of the reduced material, the said air chamber having air inlet ports in its peripheral wall each grooved by an inwardly inclined balile extending into juntaposition to the inner edge of the partition on the inner side of the air chamber, the opening in the partition on the outer .ide oi the air chamber being materially less in diameter than the opening on its inner side partition.

2. In a pulverizer embodying in series a reduction chamber, an air inlet chamber and a fan chamber, partition walls between the chambers having axially arranged openings therein for the passage of air and reduced materials, and a series 01'. inwardly inclined ballles disposed within the air inlet ch: mber and ctlective to divert heavier particles of material through the opening into the preceding reduction chamber.

3. in a pulverizer embodying in series a reduction chamber, an air inlet chamber and a an chamber, partition walls between the chambers having axially arranged openings therein for the passage of air and reduced materials, an outer peripheral wall for the air inlet chamber, said wall having a plurality 01''? air inlet openings therein, and in wardly inclined deflectors provided on the outer peripheral wall adjacent said openings for diverting heavier materials through the a: .ally arranged opening into the preceding reduction char her for further treatment.

at. In pulverizer embodying in series a reduction chamber, an air inlet chamber and a tan chamber, partition walls betwee' the chambers having a 'ially arranged opening-s therein for the passage of air and reduced materials, an outer peripheral wall for the air inletchamber, said wall having a plurality of air inlet ooenings therein, and inwardly inclined deflectors provided on the outer peripheral wall adjacent said openings for diverting heavier materials through the axially arranged opening into the preceding reduction chamber for further treatment, the diameter of said air inlet chamber enclosed by the outer peripheral wall being substantially greater than the axially arranged opening into the tan chamber.

In testimony whereoi I affix my signature.

WALTER W. PnTriBoNn. 

